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Do you know what a MERV-rating air filter is in your HVAC system? You don’t, since many people don’t realize the importance of using the right MERV-rated air filter. It is until they find themselves sneezing unstoppingly.
If your HVAC system’s air filter is unable to keep the allergens out of your living space that cause respiratory or other health issues, you are not using the right MERV-rating air filter. The MERV rating of an air filter indicates its filtration capacity; an air filter with a higher MERV rating filters more effectively.
But that doesn’t imply you should buy an air filter with a maximum MERV rating. So what MERV-rating air filter should you buy then? Keep reading this blog to determine what’s MERV rating, which is the right air filter for your HVAC system, and much more.
What Is MERV Rating on Air Filters?
MERV stands for Minimum Efficiency Reporting Value. In simpler terms, it helps you determine how effective your air filter is. The maximum MERV rating of an air filter could be 20. The higher the MERV rating your filter has, the fewer particles, including pollen, dust, pet dander, etc., can pass through it.
A 7-12 MERV-rating air filter is good for most residential HVAC systems; however, for commercial buildings, i.e., hospitals and general surgery settings, you will find an air filter with a MERV rating of 13-20. However 20 x 20 x 1 air filter can fulfil your demand of more efficient and clean air inside your home.
Higher MERV-rating air filters impact the airflow and strain your HVAC system or may even damage it. So, it is essential to choose an air filter with a good MERV rating that doesn’t affect your HVAC system negatively.
Explanation About Different MERV Air Filter Rating
Now, you are familiar with the MERV rating but have yet to discover the different MERV ratings. Without knowing about the different MERV rating filters, you won’t be able to choose the best for your settings. Here’s the list of MERV air filter ratings: –
| Air Filter MERV Rating | Microns It Can Block | Things It Can Block | Best for |
|---|---|---|---|
| 1-4 | 10 | Carpet fibers, sawdust, dust mites, and pollen | Residential Commercial Pre-filtration |
| 5-8 | 3 to 10 | Sawdust, mold spores, pollen, concrete dust, etc. | Residential, commercial, and industrial buildings |
| 9-12 | 1 to 3 | Lead dust, coal dust, legionella, general household dust, dust mites, etc. | Commercial Buildings, Schools |
| 13-16 | 0.3 to 1 | All above and sneeze particles, cosmetic dust, tobacco smoke, etc. | Hospitals, Inpatient care, general surgery facilities, etc. |
| 17-20 | 0.3 | All above and carbon dust, combustion smoke, radon progeny, sea salt, etc. | Cleanrooms, Pharmaceutical facilities |
MERV 1-4
Air filters with a MERV rating of 1-4 are commonly used for residential window air conditioning, furnaces, and pre-filtering in commercial buildings. These are the lowest-rated air filters, so they can only catch big particles. With this MERV rating, these air filters can prevent particles up to 10 microns from entering your living space, which includes carpet fibers, sawdust, dust mites, and pollen.
- Pros
- Less strain on the HVAC system
- Can be changed less frequently
- Cons
- Can’t filter small particles
- More dust and dirt entry
- You breathe in more particles
MERV 5-8
MERV 5-8 rating air filters are primarily used for paint booths and residential, commercial, and industrial buildings. They offer better filtration than the above-listed filters, but not excellent. These filters can prevent the entry of particles up to 3 to 10 microns, which include sawdust, mold spores, pollen, concrete dust, etc.
- Pros
- Improved air quality by capturing dust, pollen, mold spores, and pet dander.
- Balanced efficiency means maintaining adequate airflow.
- Cons
- Limited capture of smaller particles like bacteria and smoke.
- May require more frequent replacement due to the potential for quicker clogging.
MERV 9-12
These air filters are used in settings where there is a requirement for above-average air quality, like hospital laboratories. MERV 9-12 rating air filters can control particles up to 1 to 3 microns, which include lead dust, coal dust, legionella, general household dust, dust mites, etc.
- Pros
- Enhanced filtration capability, capturing smaller particles like mold spores, pet dander, and some allergens.
- Improved indoor air quality compared to lower MERV ratings.
- Cons
- Increased air resistance might impact airflow in some HVAC systems.
- Potential need for more frequent filter changes to maintain efficiency.
MERV 13-16
Air filters with MERV ratings between 13 and 16 are very effective, and they are generally used for residential and commercial buildings where highly effective air filtration is needed, such as inpatient care, general surgery facilities, etc. These air filters can handle all the contaminants listed for air filters with a rating of 1-12, and in addition, they effectively control sneeze particles, cosmetic dust, tobacco smoke, etc.
- Pros
- High-efficiency filtration, capturing smaller particles including smoke, bacteria, and even some viruses.
- Significantly improved indoor air quality compared to lower MERV ratings.
- Cons
- Greater air resistance may reduce airflow in certain HVAC systems.
- Higher initial cost and potential need for more frequent replacements.
MERV 17-20
As the number suggests, these are the most efficient air filters you can buy for your HVAC system. An air filter with a MERV rating between 17-20 can filter particles up to 0.3 microns in size. In addition to the contaminants listed in the products above with ratings 1-16, it can control carbon dust, combustion smoke, radon progeny, sea salt, etc.
- Pros
- Exceptional filtration such as 20 x 20 x 1 air filter captures ultra-fine particles, including viruses and smoke, providing superior indoor air quality.
- High efficiency in reducing airborne contaminants to extremely low levels.
- Cons
- Significant air resistance could impact airflow, requiring specialized HVAC systems to accommodate these filters.
- Higher initial cost and a need for meticulous maintenance to sustain efficiency.
Note: For most residential buildings, air filters with MERV ratings between 7 and 12 would be appropriate. Unnecessarily using higher-rating air filters can strain your HVAC system, decrease its efficiency, or even damage the compressor.
What MERV Rating is Best for Your Home?
If you plan to buy MERV 17-20 air filters after knowing that they offer maximum air purification, you might be wrong here. These are extremely high-rated filters that are only used in hospitals, laboratories, or clean rooms.
For residential buildings, air filters for HVAC with MERV ratings between 7 and 12 are recommended as they offer a perfect balance of air filtration and performance. Air filters beyond 12 MERV ratings indeed offer superior air filtration; however, they put much strain on your HVAC system.
Those who are planning to upgrade their air filters should refer to their system’s manual for details regarding the ideal air filter for their HVAC. You can also connect with a technician to determine the maximum MERV-rating air filter your HVAC system can support or if you have any concerns.
Final Verdict
To stay healthy, you have to breathe healthy. And to breathe healthy air, you need an air filter in your HVAC system with an appropriate MERV rating. Different MERV-rating air filters are available in the market, and you have to choose one that can filter down the maximum contaminants without straining your HVAC system.
Air filters with a MERV rating of 7-12 provide enough air filtration and are perfect for residential buildings. However, if you want to go beyond the ideal limit, you might need to consult your technician to determine whether your HVAC can work with air filters with higher MERV ratings. Consulting with HVAC professionals or considering expert recommendations can help in making an informed decision for healthier indoor air quality.
